Geology topics

Willis H. White

Publications and source records attributed to Willis H. White.

4 recordsLinked to original sources

USGS1999

Geology of Unga Island and the northwestern part of Popof Island: Chapter 2 in A geological and geophysical study of the gold-silver vein system of Unga Island, Southwestern Alaska

The first geologic map of Unga Island was published by Atwood (1911; scale 1:250,000), who correctly inferred the middle Tertiary age of the volcanic rocks and made the important distinction between the lava flows and the intrusive domes. Although Burk's (1964) reconnaissance map of the Alaska Peninsula (scale 1:250,000) has been modified in some respects, it does correct Atwood's map by replacing the Kenai Formation on northwestern Unga Island with the Unga Conglomerate and by recognizing the older Stepovak Formation elsewhere on Unga and Popof Islands. U.S. Geological Survey (USGS) field studies that were focused on the mineral-resource potential of the Alaska Peninsula began in the late 1970's. These studies led to a geologic map of the Port Moller quadrangle--including Unga Island--at 1:250,000 scale (Wilson and others, 1995), as well as summaries of mineral occurrences and geochronological studies (Wilson and others, 1988, 1994) and a formal revision of the stratigraphic units of the Alaska Peninsula (Detterman and others, 1996). As follow-up to the regional studies, a detailed study of the vein systems on Unga Island was undertaken as a collaborative effort between USGS and private industry (White and Queen, 1989). The fieldwork leading to the present report and geologic map was started in 1978 (Riehle and others, 1982) and was completed as part of the vein study. The objective was a better understanding of the geologic setting of the vein systems: the geologic history of the host rocks, the structural controls on the veins, and the types of processes that likely caused the mineralization.

Alaska↗

USGS1988

Geology and mineral resources of the Port Moller region, western Alaska Peninsula, Aleutian arc: A section in USGS research on mineral resources - 1989: Program and abstracts

Geologic mapping of the Port Moller, Stepovak Bay, and Simeonof Island quadrangles was begun under the auspices of the Alaska Mineral Resource Assessment Program (AMRAP) in 1983 . Two important mineral deposits are located in the Port Moller quadrangle; the Pyramid prospect is the largest copper porphyry system in the Aleutian Arc, and the Apollo Mine is the only gold mine to reach production status in the Aleutian Arc.

Alaska↗

USGS1988

Brief descriptions of mines, prospects, and mineral occurrences in the Port Moller and Stepovak Bay quadrangles, Alaska peninsula

This report contains brief descriptions of known mines, prospects, and mineral occurrences in the Port Moller and Stepovak Bay quadrangles on the Alaska Peninsula. These quadrangles, and the adjoining Simeonof Island quadrangle to the south were the subject of an Alaska Mineral Resource Assessment Program (AMRAP) mapping and mineral resource assessment project. This compilation of descriptions was made from the published literature (Wilson and others, 1986) and unpublished reports and data of The Aleut Corporation, the U.S. Bureau of Mines, and the U.S. Geological Survey. The initial compilation was primarily based on data from Cobb (1972) and MacKevett and Holloway (1977), however information provided by The Aleut Corporation and data gathered during the Port Moller AMRAP project added most of the information in the descriptions and the database. Compilation of this database is an ongoing process and this is a progress report of work completed to date. The authors would appreciate any corrections or additional information that users may be able to contribute. To facilitate active use of the descriptions, where information is not available for a particular field in the database, it is left blank so that the use can write in data as they obtain it.

Alaska↗

USGS1987

Geology of the Ar Rahail ancient gold mine, Kingdom of Saudi Arabia

The Ar Rahail ancient gold mine is a collection of ancient workings in metasedimentary rocks of the Murdama Group adjacent to, and above the flanks of the Rahail stock. Injection of mafic dikes of regional origin was followed by emplacement of the Rahail stock, which consisted of early dikes of porphyritic biotite-bearing hornblende granodiorite, and a later cupola of porphyritic monzogranite. Crystallization of the cupola produced a molybdenum-bearing quartz vein stockwork. Intrusion-heated fluids developed chlorite and sericite alteration zones in the older granodiorite dikes. Pre-existing northwest-trending faults, possibly re-opened by stock emplacement, were invaded by later fluids that precipitated barren quartz veins and, in the adjacent faulted wall rocks, anomalous gold and arsenic. Gold, however, is restricted to the narrow structures, and, although values as much as 4.2 g/t are present, the tonnages are inadequate for profitable mining. No further work is recommended, because the hoped for dissemination of gold between faults does not exist.

Open-File Report↗